Prosthetic Mitral Valve and Delivery Method

ABSTRACT

A valve prosthesis and methods for implanting the prosthesis are provided. The prosthesis generally includes a self-expanding frame and two or more engagement arms. A valve prosthesis is sutured to the self-expanding frame. Each engagement arm corresponds to a native mitral valve leaflet. At least one engagement arm immobilizes the native leaflets, and holds the native leaflets close to the main frame. The prosthetic mitral valve frame also includes two or more anchor attachment points. Each anchor attachment point is attached to one or more anchors that help attach the valve prosthesis to the heart.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to artificial heart valves. Morespecifically, the present invention is directed to artificial mitralvalve prostheses and method of implanting the prostheses leading toreduction of myocardial wall tension and the repair of mitral valveinsufficiency.

2. Background

The mitral valve is a functional organ composed of multiple dynamicallyinterrelated units. During cardiac cycle, the fibrous skeleton, theanterior and posterior leaflets, the papillary muscles, the chordaetendinea, and the ventricular and atrial walls all interplay to render acompetent valve. The complex interaction between the mitral valve andthe ventricle by the subvalvular apparatus (the papillary muscles andthe chordae tendinea) is essential in maintaining the continuity betweenthe atrio-ventricular ring (which is part of the fibrous skeleton of theheart) and the ventricular muscle mass, which provides for the normalfunctioning of the mitral valve.

Like all heart valves, the mitral valve exhibits two types ofpathologies: regurgitation (i.e., abnormal leaking of blood from theleft ventricle, through the mitral valve, and into the left atrium, whenthe left ventricle contracts) and stenosis (i.e., narrowing of theorifice of the mitral valve of the heart). Regurgitation is the morecommon of the two defects. Typically, either defect can be treated bysurgical repair. However, surgical repair is not always feasible sincemany patients requiring mitral valve replacement are inoperable ordeemed to pose too high a surgical risk because of extensive fibrosis,leaflets calcification, or massive chordae rupture. Further, suchsurgical procedures are traumatic. Additionally, surgical procedures canlead to an interruption of the mitral annulus-papillary musclecontinuity, which accounts for changes in geometry mechanics andperformance of the left ventricle. These problems are lessened by theemerging techniques for minimally invasive mitral valve repair, butstill many of those techniques require arresting the heart and funnelingthe blood through a heart-lung machine, which can also be traumatic forpatients.

In certain cases, the mitral valve cannot be repaired and must bereplaced. Valve replacement can create additional problems includinglimitation of the mitral flow during exercise due to a small effectiveorifice area and high cardiac output imposed by a smaller sizeartificial valve as compared with the natural valve orifice area.Further, the rigid structure of an artificial valve prevents thephysiologic contraction of the posterior wall of the left ventriclesurrounding the mitral annulus during systole. Also, myocardial rupturecan result from excision or stretching of the papillary muscle in a thinand fragile left ventricle. Additionally, chordae rupture can also occurdue to the chordae rubbing against the artificial valve over time,leading to increased heart wall stress. It has been shown that severingthe chordae can lead to a 30% reduction in chamber function. Thus,mitral valve replacement has a high mortality rate in very sick, chronicheart failure patients.

The chordae tendinea, which connect the valve leaflets to the papillarymuscles (PM) act like “tie rods” in an engineering sense. Not only dothe chordae tendinea prevent prolapse of the mitral valve leafletsduring systole, but they also support the left ventricular muscle massthroughout the cardiac cycle. To function adequately, the mitral valveopens to a large orifice area and, for closure, the mitral leaflets havean excess surface area (i.e. more than needed to effectively close themitral orifice). On the other hand, systolic contraction of theposterior ventricular wall around the mitral annulus (MA) creates amobile D-shaped structure with sphincter-like function which reduces itsarea by approximately 25% during systole, thus exposing less of themitral leaflets to the stress of the left ventricular pressure and flow.

It has been long postulated that the structural integrity of the MA-PMcontinuity is essential for normal left ventricular function. Recentevidence supports the concept that preservation of the subvalvularapparatus with the MA-PM continuity in any procedure on the mitral valveis important for the improved long-term quality and quantity of lifefollowing valve replacement. Maintaining the MA-PM continuity, thus,appears to provide a substantial degree of protection from thecomplications associated with valve replacement.

Therefore, what is needed is a mitral valve prosthesis and method ofimplantation that minimizes the traumatic impact on the heart whileeffectively replacing native leaflet function. A consistent,reproducible, and safe method to introduce a prosthesis into the mitralposition in a minimally invasive fashion could be attractive fornumerous reasons: a) it can treat both functional and degenerativemitral regurgitation (MR); b) it can treat mitral stenosis; c) it canoffer a remedy to inoperable patients, high risk surgical patients, andthose that cannot tolerate bypass; d) it can allow a broad range ofpractitioners to perform mitral valve procedures; and/or e) it canenable more consistency in measuring outcome.

BRIEF SUMMARY OF THE INVENTION

Provided herein are mitral valve prostheses and methods for implantingthe prostheses in the heart. The prostheses generally include aself-expanding frame and two or more engagement arms. A valve prosthesisis sutured to the self-expanding frame. Each engagement arm correspondsto a native mitral valve leaflet. At least one engagement armimmobilizes the native leaflets, and holds the native leaflets close tothe main frame. Such configuration achieves numerous goals. For example,such configuration achieves one or more of the following: prevents thenative leaflets from obstructing flow through the left ventricularoutflow tract (LVOT); prevents the native leaflets from interacting withthe prosthetic leaflets; recruits the native leaflets in minimizingperi-valvular leaks; maintains proper alignment of the valve prosthesis;avoid systolic anterior mobility; and maintains valve stability bypreventing migration of the valve into the atrium or ventricle andprevents damage to the native chordae. Additionally, the prostheticmitral valve frame can include two or more anchor attachment points.Each anchor attachment point can be attached to one or more anchors thathelp attach the mitral valve to the heart. Such configuration providesadded stability to the prosthetic mitral valve and prevents damage tothe native chordae. The design of the prosthesis also mimics the nativevalve and supports a non-circular in vivo configuration, which betterreflects native valve function.

In certain embodiments, the mitral valve prosthesis comprises anexpandable inflow region formed of a plurality of cells, an expandableoutflow region formed of a plurality of cells, and a prosthetic valve.The expandable inflow region has a cross-sectional diameter larger thanthe annulus of the native mitral valve and can be configured to expandwithin and support against the walls of the left atrium. The expandableoutflow region can be configured to expand within and support againstthe native mitral valve annulus and comprises two or more engagementarms and at least two anchor attachment points.

In certain embodiments, a mitral valve disorder in a patient's heart canbe treated by a method comprising the steps of: (a) inserting a deliverydevice into the left ventricle of the heart, (b) advancing a mitralvalve prosthesis via the delivery device into the left ventricle of theheart, (c) advancing the delivery device into the native mitral valvesuch that the engagement arms seat on the outer surface of the nativemitral valve leaflets, (d) attaching the mitral valve prosthesis to theheart via at least one anchor, and (e) adjusting tension on the anchorto prevent peri-valvular leakage.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying figures, which are incorporated herein, form part ofthe specification and illustrate embodiments of a mitral valveprosthesis and methods of implantation. Together with the description,the figures further serve to explain the principles of and to enable aperson skilled in the relevant art(s) to make, use, and implant thevalve prosthesis described herein. In the drawings, like referencenumbers indicate identical or functionally similar elements.

FIG. 1 is a perspective view of a mitral valve prosthesis, according toan aspect of this disclosure.

FIG. 2 is a perspective view of a frame of a mitral valve prosthesis anda close-up view of the frame showing the anchor attachment points,according to an aspect of this disclosure.

FIG. 3A is a schematic view of a valve prosthesis and delivery systemaccording to an aspect of this disclosure.

FIG. 3B is a schematic view of a valve prosthesis and delivery systemaccording to an aspect of this disclosure.

FIG. 3C is a schematic view of a valve prosthesis and delivery systemaccording to an aspect of this disclosure.

FIG. 3D is a schematic view of a valve prosthesis and delivery systemaccording to an aspect of this disclosure.

FIG. 3E is a schematic view of a valve prosthesis and delivery systemaccording to an aspect of this disclosure.

FIG. 3F is a schematic view of a valve prosthesis and delivery systemaccording to an aspect of this disclosure.

FIG. 4A is a perspective view of a mitral valve prosthesis, according toan aspect of this disclosure.

FIG. 4B is a perspective view of a mitral valve prosthesis, according toan aspect of this disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of mitral valve prostheses andmethods for implantation refers to the accompanying figures thatillustrate exemplary embodiments. Other embodiments are possible.Modifications can be made to the embodiments described herein withoutdeparting from the spirit and scope of the present invention. Therefore,the following detailed description is not meant to be limiting.

FIG. 1 is a perspective view of a mitral valve prosthesis 100, inaccordance with one embodiment presented herein. Prosthesis 100comprises a non-cylindrical inner support structure 102 located at theoutflow end of mitral valve prosthesis 100. Non-cylindrical shapes canbe used to improve the anchoring and/or orientation of the prostheticvalve at the desired implantation site. In addition, inner supportstructure 102 can have one or more sections configured to expand to arestricted or preset diameter rather than to expand until restrained bysurrounding anatomical structures. Control of the expansion diameterprovides a portion of inner support structure 102 with a predeterminedconfiguration irrespective of the surrounding anatomy. The valvegeometry in the expanded configuration can be enhanced in prostheseswith controlled expansion diameters.

In one aspect of the invention, inner support structure 102 can comprisea generally axially-curved configuration or a concave configuration.Such configurations can further resist deviations from the optimal valvesupport expansion configuration. This is because variations in themechanical stress exerted from the inflow zone of proximal section 116and/or outflow zone of distal section 112, caused by anatomical andpathological variations of surrounding structures, will be dispersedalong the entire length of prosthesis 100. As used herein the term“distal” is understood to mean downstream to the direction of bloodflow. The term “proximal” is intended to mean upstream to the directionof blood flow. As a result, any detrimental effects to prevent expansionof valve prosthesis 100 to its optimal expansion configuration areminimized and prevented. In comparison, a prosthesis frame with a morecylindrical shape responds less predictably to variations in a patient'sanatomy and can kink and/or bow after implantation. Such kinking and orbowing disrupts the geometry of the valve that is resistant to expansionvariations of adjacent zones. By providing a consistent expandedconfiguration for the valve prosthesis 100 that is resistant toexpansion changes of adjacent zones, a consistent valve geometry isachieved and valve function can be improved.

Mitral valve prosthesis 100 also includes an outer support structure 104located at the inflow end of mitral valve prosthesis 100. As shown,mitral valve prosthesis 100 includes two engagement arms 106 attached toinner support structure 102 to anatomically match the native mitralvalve leaflets (not shown). Upon implantation outer engagement arms 106clamp and immobilize the native mitral valve leaflets, and hold thenative leaflets close to outer support structure 104. Each outerengagement arm 106 includes a trough and an upward concave structurehaving ends meeting at commissure post 108. In one aspect of theinvention, the inner support structure 102 comprises two commissureposts 108, wherein ends of the engagement arms are each coupled to oneof the commissure posts. In another embodiment, the inner supportstructure 102 further comprises more than two commissure posts 108,wherein ends of the engagement arms are each coupled to one of thecommissure posts. Inner support structure 102 further includes anopening to facilitate attaching outer support structure 104 to innersupport structure 102. In a further aspect of the invention, innersupport structure 102 includes commissural sealing members (not shown)to provide an effective seal between the outer support structure 104 ofthe mitral valve prosthesis 100 and the walls of the atrium (not shown),thereby sealing the native commissures of the heart and preventingperi-valvular leakage.

Inner support structure 102 includes a generally uniform, circularcross-section along the length of the longitudinal axis of valveprosthesis 100. In an alternative embodiment, proximal section 116 canalso include fixation barbs to provide further fixation and to preventmigration of prosthesis 100 into the ventricle. As shown, distal section112, narrow throat section 114, and proximal section 116 includediamond-shaped cells 110. Alternative shapes and configurations of thecells (or struts) 110 can be employed. The diamond-shaped cells 110 aregenerally equal in size. However, each column of cells can havedifferent sizes. Alternatively, cells located near the distal section112 of prosthesis 100 can be smaller than cells located near proximalsection 116.

Any suitable combination of these embodiments can also be used. Forexample, for each cell, the location of the junction of members betweenadjacent cells can be positioned asymmetrically. Inner support structure102 can comprise curvilinear structural members to form asymmetricalcells. In an alternative embodiment, inner support structure 102 cancomprise structural members formed in a generally zig-zag configurationto form symmetrical or asymmetrical cells. The zig-zag configuration isbelieved to improve upon otherwise straight members, by distributing thestress associated with radial expansion and contraction to a pluralityof points between junctions. As with the above embodiments, innersupport structure 102 can be configured with heterogeneous patterns ofcells or homogeneous patterns of cells, or both.

Individual cells of a prosthesis frame can be characterized by theirrelative length and width. It is generally preferred that the ratio ofthe cell length to width be about 0.5 to about 3.0, more preferablyabout 1.5 to 2.5 and most preferably about 1.75 to about 2.25. Cellconfigurations having size ratios generally within these ranges arebelieved to have improved expansion and structural characteristics.

Distal section 112 can be formed in a straight fashion (i.e.,cylindrical and parallel to the longitudinal axis of prosthesis 100) orin a flared fashion (i.e., diverging away from the longitudinal axis ofprosthesis 100). Proximal section 116 is generally formed to bulgeoutward from narrow throat section 114, and can be formed straight orflared outward. Proximal section 116 is the blood inlet end of valveprosthesis 100. In one aspect of the disclosure, proximal section 116 iswider than narrow throat section 114, and is wider than the native valvesegment at the native valve annulus. Such a configuration preventsmigration of prosthesis 100 into the ventricle and improves sealing ofprosthesis 100 against the atrial wall.

Inner support structure 102 is also configured to be expandable(preferably self-expandable), and can be formed of a memory alloy suchas NITINOL. Other biocompatible metals can also be used. Outer supportstructure 104 can also be formed of a memory alloy such as NITINOL, orother biocompatible metals. Inner support structure 102 and outersupport structure 104 can be integrally formed, or can comprise separatemodular components that are attached to one another. In one embodiment,inner support structure 102 is designed to flex and deform so as tomimic the natural cardiac movements of the heart through the cardiaccycle. In another embodiment, inner support structure 102 is designed ina rigid fashion to avoid flexing or deformation during the cardiaccycle.

A prosthetic valve 118 can be attached to inner support structure 102.In one embodiment, valve 118 is sewn onto inner support structure 102 asdescribed in U.S. Patent Application Publication No. 2008/0071368, whichis incorporated herein by reference in its entirety. In one aspect ofthe disclosure, valve 118 can be formed of a biocompatible syntheticmaterial, synthetic polymer, an autograft tissue, xenograft tissue, orother alternative materials. In a further aspect of the invention, valve118 can be a tri-leaflet bovine pericardium valve, a bi-leaflet valve,or any other suitable valve.

Alternative designs can include three engagement arms, three leaflets,three anchor attachment points, and/or three commissure posts.

In one aspect of the invention, outer support structure 104 can becurved to deform and raise up the native annulus and tension thechordae. See U.S. Application Number INSERT FOR P00003667.USU1, which isincorporated herein by reference in its entirety.

FIG. 2 is a perspective view of a frame of a mitral valve prosthesis200, in accordance with an alternative aspect of the invention. Similarto mitral valve prosthesis 100 of FIG. 1, mitral valve prosthesis 200includes an outer support structure 204 and an inner support structure202, which includes a distal section 212, a relatively narrow throatsection 214, and a proximal section 216. Inner support structure 202includes outer engagement arms 206. As shown, distal section 212, narrowthroat section 214, and proximal section 216 include diamond-shapedcells 210. Alternative shapes and configurations of the cells (orstruts) can be employed. Mitral valve prosthesis 200 includes all thefeatures of prosthesis 100 and further includes anchor attachment points208 on inner support structure 202. The anchor attachment points 208 canattach to the heart via one or more anchors to provide further fixationsupport and to prevent migration of prosthesis 200 into the ventricle.The anchors disclosed herein are very robust and greatly improve thestability of mitral valve prosthesis 200 which lessens the possibilityof migration due to chordae rupture. The anchors take the strain off ofthe native chordae and help reduce the tendency for them to break overtime. In addition, the anchors can be tensioned to help prevent and/orstop peri-valvular leakage.

Like prosthesis 100, a prosthetic valve (not shown) can be attached toinner support structure 202. In one aspect of the invention, theprosthetic valve is sewn onto inner support structure 202, as describedin U.S. Patent Application Publication No. 2008/0071368, which isincorporated herein by reference in its entirety. The prosthetic valvecan be formed of a biocompatible synthetic material, synthetic polymer,an autograft tissue, xenograft tissue, or other alternative materials.In a further aspect of the invention, inner support structure 202includes commissural sealing members (not shown) to provide an effectiveseal between the outer support structure 204 of the mitral valveprosthesis 200 and the walls of the atrium (not shown), thereby sealingthe native commissures of the heart and preventing peri-valvularleakage.

Referring now to FIGS. 3A-3F, a method of implanting a mitral valveprosthesis 302 will now be described. Mitral valve prosthesis 302includes all the features of valve prostheses 100 and 200. In one aspectof the invention, delivery device 340 is inserted through mitral annulus317 into the left ventricle and mitral valve prosthesis 302 can bedeployed into mitral annulus 317. As shown, papillary muscle 316 andchordae 314 are positioned in the left ventricle. Chordae 314 connectnative valve leaflets (not shown) to papillary muscle 316. Deliverydevice 340 includes a deployment element 360 having a distal tip 308.Deployment element 360 is advanced into the left ventricle such that theengagement arms 306 of the mitral valve prosthesis 302 seat on the outersurface of the native mitral valve leaflets at the mitral annulus 317.Delivery device 340 can be rotated and adjusted as necessary to alignthe valve prosthesis so that engagement arms 306 are positioned to clampthe native valve leaflets. Proper seating of the mitral valve prosthesis302 at the mitral annulus 317 is achieved by the engagement arms 306capturing the native mitral valve leaflets. The radial force generatedby the mitral valve prosthesis 302 in the atrium against engagement arms306 creates a “sandwich effect” by pinching the native mitral valveleaflets and atrial tissue against the inner support structure of mitralvalve prosthesis 302.

In a further aspect of the invention, the user can control the speed ofdeployment of valve prosthesis 302 by modifying the rate at which theuser pushes deployment element 360 in the distal direction. In certaininstances, the user may wish to reposition the prosthetic valve afterbeginning to deploy the prosthetic valve. The user can accomplish thisby moving the entire delivery device 340 in a distal or proximaldirection. In certain embodiments, delivery device 340 and deploymentelement 360 can be generally cylindrical in shape.

In one aspect of the invention, delivery device 340 is a trocar. Inanother aspect of the invention, the delivery device 340 is a catheter.In certain embodiments, parts of delivery device can be made frombiocompatible materials, such as certain biocompatible polymers andbiocompatible metals known in the art.

In a further aspect of the invention, deployment element 360 is attachedto anchor attachment points 312 of mitral valve prosthesis 302 viaanchors 310. In one aspect of the invention, anchors 310 are attached ata first end to attachment points 312 of mitral valve prosthesis 302prior to delivery of mitral valve prosthesis 302. A second end ofanchors 310 extend through distal tip 308 of deployment element 360though delivery device 340 to the outside of the patient. In one aspectof the invention, anchors 310 are artificial chordae.

In one aspect of the invention, each anchor attachment point 312includes a single eyelet. In another aspect of the invention, eachanchor attachment point 312 includes at least two eyelets. In anotheraspect of the invention, each anchor attachment point 312 includes atleast one hook. In another aspect of the invention, each anchorattachment point 312 includes at least one clip. In another aspect ofthe invention, each anchor attachment point 312 includes at least onescrew. In another aspect of the invention, each anchor attachment point312 includes at least two of any combinations of an eyelet, a hook, aclip and/or a screw.

In one aspect of the invention, anchor 310 is a suture comprised of abiocompatible material. In another aspect of the invention, anchor 310is a wire comprised of a biocompatible material. In another aspect ofthe invention, anchor 310 is a chord comprised of a biocompatiblematerial. In another aspect of the invention, the anchor is anybiocompatible material. In one aspect, the biocompatible material islinearly elastic. In another aspect, the biocompatible material isviscoelastic. In yet another aspect, the biocompatible material can beengineered to have any desired property. In one embodiment, thebiocompatible material can be a composite fiber of PTFE, elastane, andbinder. In another embodiment, the biomaterial can also be an autograft,allograft, or xenograft used as a transplant material. In anotherembodiment, the biomaterial can be formed of a memory alloy such asNITINOL. In yet another embodiment, the biomaterial can be anybiocompatible polymer or biocompatible metal known in the art. In oneaspect, the elastic nature of the biocompatible material is optimized soit can provide a constant force and not elongate over time. In anotheraspect, the biocompatible material can be reinforced to have optimumfatigue performance. In one embodiment, the anchor is configured tofunction as a tether. In yet another embodiment, the anchor can beconfigured to function as an artificial chordae. In still anotherembodiment, the anchor can be configured to function as an anchoringelement.

After deployment of mitral valve prosthesis 302, delivery device 340 anddeployment element 360 are retracted while mitral valve prosthesis 302remains attached to delivery device 340 and distal tip 308 of thedeployment element 360 via anchors 310.

As shown in FIGS. 3C-3D, the second ends of anchors 310 are disengagedfrom the distal tip 308 of the deployment element 360 and passed throughholes 326 of an anchoring element 318 into an anchoring element deliverydevice 320. In a further aspect of the invention, anchors 310 passacross lock 330 of anchoring element 318. In one aspect of theinvention, anchoring element 318 is a clip and includes jaws 324. Inalternative aspect of the invention, the anchoring element 318 can be ahook, screw, or other attachment known in the art. In one aspect of theinvention, the anchoring element delivery device 320 is cylindrical inshape.

In one aspect of the invention, anchors 310 are woven through holes 326in the anchoring element 318 and then passed into an anchoring elementdelivery device 320 through opening 328 in the anchoring elementdelivery device 320. The jaws 324 of the anchoring element 318 areprovided to attach anchoring element 318 and anchors 310 to hearttissue. In one aspect of the invention, jaws 324 of the anchoringelement 318 can attach to a papillary muscle 316 of the heart bygripping and holding onto papillary muscle 316 tissue within jaws 324.In one aspect of the invention, jaws 324 are configured to allow forproper tensioning of anchors 310. For example, when jaws 324 are open,anchors 310 can be tensioned through anchor element delivery device 320by adjusting the length of anchors 310. When jaws 324 are closed, lock330 on anchoring element 318 clamps anchors 310 such that the length ofanchors 310 cannot be adjusted to adjust the tension. In one aspect,jaws 324 are closed onto heart tissue after proper tensioning of theanchors 310 is achieved. As disclosed herein, jaws 324 are open whentissue or other heart structure can be passed into jaws 324 into aninterior area of anchoring element 318. Jaws 324 are opened to allowjaws 324 to attach to heart tissue and to allow for tensioning ofanchors 310.

In another aspect of the invention, anchors 310 can be attached topapillary muscle 316 or other heart structure prior to implantation ofmitral valve prosthesis 302. In this aspect, the practitioner would beable to check the securement of anchoring element 318 prior tocommencing valve implantation.

As shown in FIG. 3E, the anchoring element 318 and anchors 310 areadvanced into the left ventricle via the anchoring element deliverydevice 320 in order to attach to heart tissue or other structure in theleft ventricle. In one embodiment, the anchoring element 318 is attachedto a papillary muscle 316 of the heart. As a result, mitral valveprosthesis 302 is connected to the papillary muscle 316 of the heartthough anchor attachment points 312, anchors 310, and anchoring element318. In one embodiment, the anchoring element 318 is attached to secondends of the anchors 310.

FIG. 3F depicts a mitral valve prosthesis 302 properly positioned at themitral annulus 317 and attached to the papillary muscles 316 of theheart via the anchors 310. Prior to closing jaws 324 on anchoringelement 318, tension on the anchors 310 is adjusted as required in orderto secure the mitral valve prosthesis 302 at the mitral annulus 317. Ina further aspect of the invention, a practitioner can check forperi-valvular leakage (PVL) prior to completion of the valve replacementprocedure. If leakage is present, anchors 310 can be tensioned to stopthe leakage by opening jaws 324 on anchoring element 318 to release lock330 to adjust the length of anchors 310 through anchoring elementdelivery device 320. After the practitioner verifies that no leakage ispresent around mitral valve prosthesis 302, anchoring element deliverydevice 320 is detached and withdrawn.

The anchors disclosed herein are very robust and greatly improve thestability of mitral valve prosthesis 200 which lessens the possibilityof migration due to chordae fracture. The anchors take the strain off ofthe native chordae and help reduce the tendency for them to break overtime. In addition, the anchors can be tensioned to add to the sandwicheffect and help prevent and/or stop peri-valvular leakage.

FIG. 4A is a perspective view of a mitral valve prosthesis 400, inaccordance with an alternative aspect of the invention. Mitral valveprosthesis 400 includes an outer support structure 404 and an innersupport structure 412. In one aspect of the invention, inner supportstructure 412 includes at least two outer engagement arms 406 and atleast two commissural sealing members 420. Each commissural sealingmember 420 is positioned at approximately 90 degrees to each engagementarm 406. In alternative aspects of the invention, the commissuralsealing members 420 can be positioned at angles greater than or lessthan 90 degrees to each engagement arm 406. As shown, the outer supportstructure includes diamond-shaped cells (or struts) 422. Alternativeshapes and configurations of the cells can be employed. Inner supportstructure 412 further includes two anchor attachment points 424. Eachanchor attachment point 424 is configured to attach to the heart via ananchor 414 to provide fixation support and to prevent migration ofprosthesis 400 into the ventricle. Each anchor 414 further includes atether 416 which provides further stability to the mitral valveprosthesis 400. A first end of each anchor 414 is attached to the anchorattachment points 424, while a second end of the anchor is attached toan anchoring element 418. In one aspect of the invention, anchoringelement 418 is a hook. In alternative aspects of the invention, theanchoring element 418 can be a clip or a screw. The anchoring element418 is configured to attach to the heart to provide further fixationsupport and to prevent migration of prosthesis 400 into the ventricle.In one aspect, anchoring element 418 is configured to attach to the wallof the left ventricle. In an alternative aspect, the anchor 414 isconfigured to be sutured to the heart. Like prosthesis 100, a prostheticvalve 408 can be attached to inner support structure 412 at specificpositions 410. In one embodiment, the prosthetic valve is sewn ontoinner support structure 412 as described in U.S. Patent ApplicationPublication No. 2008/0071368, which is incorporated herein by referencein its entirety. The prosthetic valve can be formed of a biocompatiblesynthetic material, synthetic polymer, an autograft tissue, xenografttissue, or other alternative materials.

In one aspect of the invention, anchor 414 is a suture comprised of abiocompatible material. In another aspect of the invention, anchor 414is a wire comprised of a biocompatible material. In yet another aspectof the invention, anchor 414 is a chord comprised of a biocompatiblematerial. In another aspect of the invention, anchor 414 is anybiocompatible material. In one aspect, the biocompatible material islinearly elastic. In another aspect, the biocompatible material isviscoelastic. In yet another aspect, the biocompatible material can beengineered to have any desired property. In one embodiment, thebiocompatible material can be a composite fiber of PTFE, elastane, andbinder. In another embodiment, the biomaterial can also be an autograft,allograft, or xenograft used as a transplant material. In anotherembodiment, the biomaterial can be formed of a memory alloy such asNITINOL. In yet another embodiment, the biomaterial can be anybiocompatible polymer or biocompatible metal known in the art. In oneaspect, the elastic nature of the biocompatible material is optimized soit can provide a constant force and not elongate over time. In anotheraspect, the biocompatible material can be reinforced to have optimumfatigue performance. In one aspect of the invention, anchor 414 isconfigured to function as a tether. In yet another aspect, anchor 414can be configured to function as an artificial chordae. In still anotheraspect, the anchor can be configured to function as an anchoringelement.

FIG. 4B is a perspective view of a mitral valve prosthesis 400positioned at the mitral annulus 426 so that the engagement arm 406 ispositioned to clamp the native valve leaflet 422. The commissuralsealing members 420 are positioned at 90 degrees to the engagement arm406 to provide an effective seal between the outer support structure 404of the mitral valve prosthesis 400 and the walls of atrium 428, therebysealing the native commissures of the heart and preventing peri-valvularleakage. In alternative aspects of the invention, the commissuralsealing members 420 can be positioned at angles greater than or lessthan 90 degrees to the engagement arm 406. The frame seating relies onthe engagement arms 406 pulling tension on the native chordae tendinaeand the sandwich effect of the native valve leaflet 422 and the atrialtissue 424 being trapped by the engagement arm 406 and the outer supportstructure 404 of the mitral valve prosthesis 400.

Provided herein are also methods for treating mitral valve disorders inpatients. In one embodiment, the method for treating mitral valvedisorders in a patient's heart comprises a) inserting a delivery deviceinto the left ventricle of the heart, b) advancing a mitral valveprosthesis via the delivery device into the left ventricle of the heart,c) advancing the delivery device into the native mitral valve such thatthe engagement arms seat on the outer surface of the native mitral valveleaflets, d) attaching the mitral valve prosthesis to the heart via atleast one anchor, and e) adjusting tension on the anchor to preventperi-valvular leakage. The mitral valve prosthesis comprises anexpandable inflow region formed of a plurality of cells and isconfigured to expand within and support against the walls of the leftatrium. The expandable inflow region has a cross-sectional diameterlarger than the annulus of the native mitral valve. The mitral valveprosthesis also comprises an expandable outflow region formed of aplurality of cells and configured to expand within and support againstthe native mitral valve annulus, wherein the expandable outflow regionincludes two or more engagement arms, at least two anchor attachmentpoints, and a prosthetic valve.

In one aspect of the invention, the method involves inserting thedelivery device transfemorally into the left ventricle of the heart. Inanother embodiment, the method involves inserting the delivery devicetransseptally into the left ventricle of the heart. In yet anotherembodiment, the method involves inserting the delivery devicetransapically into the left ventricle of the heart.

In one aspect of the invention, at least one anchor attachment point ofthe mitral valve used in treating the mitral valve disorder is attachedto a proximal end of at least one anchor prior to advancing a mitralvalve prosthesis via the delivery device into the left ventricle of theheart. In one aspect, at least one anchor attachment point of the mitralvalve used in treating the mitral valve disorder is attached to aproximal end of at least one anchor after the mitral valve prosthesis ispositioned at the mitral annulus.

In one aspect, the distal end of at least one anchor attachment point ofthe mitral valve used in treating the mitral valve disorder is attachedto the heart prior to advancing a mitral valve prosthesis via thedelivery device into the left ventricle of the heart. In another aspect,the distal end of at least one anchor attachment point of the mitralvalve used in treating the mitral valve disorder is attached to theheart only after the mitral valve prosthesis is positioned at the mitralannulus.

In another aspect, the distal end of the anchor is attached to theheart. In another aspect, the anchor is sutured to the heart. In oneaspect, the anchor is attached to the heart via an anchoring element. Inalternative aspects of the invention, the anchoring element can be ahook, a clip, or a screw. In one aspect, the anchoring element of themitral valve used in the method of treating a mitral valve disorder canbe configured to attach to a papillary muscle of the heart. In anotherembodiment, the anchoring element can be configured to attach to thewall of the left ventricle. In yet another embodiment, the anchor can beconfigured to function as an artificial chordae. In one aspect, theanchor comprises a biocompatible material.

In one aspect of the invention, the expandable outflow region of themitral valve used in the method of treating a mitral valve disorderfurther comprises at least one commissural sealing member. In anotheraspect, the expandable outflow region comprises at least two commissuralsealing members. In another aspect, the expandable outflow regionfurther comprises two or more commissure posts, wherein ends of theengagement arms are each coupled to one of the commissure posts.

The foregoing description has been presented for purposes ofillustration and enablement, and is not intended to be exhaustive or tolimit the invention to the precise form disclosed. Other modificationsand variations can be possible in light of the above teachings. Theembodiments and examples were chosen and described in order to bestexplain the principles of the invention and its practical applicationand to thereby enable others skilled in the art to best utilize theinvention in various embodiments and various modifications as are suitedto the particular use contemplated. It is intended that the appendedclaims be construed to include other alternative embodiments of theinvention.

What is claimed is:
 1. A mitral valve prosthesis comprising: a) anexpandable inflow region formed of a plurality of cells and configuredto expand within and support against the walls of the left atrium,wherein the expandable inflow region has a cross-sectional diameterlarger than the annulus of the native mitral valve; b) an expandableoutflow region formed of a plurality of cells and configured to expandwithin and support against the native mitral valve annulus, wherein theexpandable outflow region comprises: i) two or more engagement arms; andii) at least two anchor attachment points; and c) a prosthetic valve. 2.The mitral valve prosthesis of claim 1, wherein each anchor attachmentpoint is attached to a proximal end of one or more anchor.
 3. The mitralvalve prosthesis of claim 2, wherein the anchor comprises abiocompatible material.
 4. The mitral valve prosthesis of claim 2,wherein a distal end of each anchor is further attached to an anchoringelement.
 5. The mitral valve prosthesis of claim 4, wherein theanchoring element is a hook.
 6. The mitral valve prosthesis of claim 4,wherein the anchoring element is a clip.
 7. The mitral valve prosthesisof claim 4, wherein the anchoring element can be adjusted to adjusttension on the anchor.
 8. The mitral valve prosthesis of claim 4,wherein the anchoring element is configured to attach to the wall of theleft ventricle.
 9. The mitral valve prosthesis of claim 4, wherein theanchoring element is configured to attach to a papillary muscle of theheart.
 10. The mitral valve prosthesis of claim 2, wherein the anchor isconfigured to function as an artificial chordae.
 11. The mitral valveprosthesis of claim 10, wherein a distal end of the anchor is sutured toa papillary muscle of the heart.
 12. The mitral valve prosthesis ofclaim 3, wherein the biocompatible material is linearly elastic.
 13. Themitral valve prosthesis of claim 3, wherein the biocompatible materialis viscoelastic.
 14. The mitral valve prosthesis of claim 1, wherein theexpandable outflow region further comprises at least two commissuralsealing members.
 15. The mitral valve prosthesis of claim 14, whereinthe commissural sealing members extend at an angle of about 90 degreesto the engagement arms.
 16. The mitral valve prosthesis of claim 14,wherein the commissural sealing members are configured to seal nativecommissures of the heart and prevent peri-valvular leakage (PVL). 17.The mitral valve prosthesis of claim 1, wherein the prosthetic valve issutured to the expandable inflow region.
 18. The mitral valve prosthesisof claim 1, wherein the anchor attachment points comprise two or moreeyelets.
 19. The mitral valve prosthesis of claim 1, wherein theexpandable outflow region further comprises two or more commissureposts, wherein ends of the engagement arms are each coupled to one ofthe commissure posts.
 20. A method of treating a mitral valve disorderin a patient's heart, comprising: a) inserting a delivery device intothe left ventricle of the heart; b) advancing a mitral valve prosthesisvia the delivery device into the left ventricle of the heart, whereinthe mitral valve prosthesis comprises: 1) an expandable inflow regionformed of a plurality of cells and configured to expand within andsupport against the walls of the left atrium, wherein the expandableinflow region has a cross-sectional diameter larger than the annulus ofthe native mitral valve; 2) an expandable outflow region formed of aplurality of cells and configured to expand within and support againstthe native mitral valve annulus, wherein the expandable outflow regioncomprises: i) two or more engagement arms; and ii) at least two anchorattachment points; and 3) a prosthetic valve; c) advancing the deliverydevice into the native mitral valve such that the engagement arms seaton the outer surface of the native mitral valve leaflets; d) attachingthe mitral valve prosthesis to the heart via at least one anchor; and e)adjusting tension on the anchor to prevent PVL.
 21. The method of claim20, wherein at least one anchor attachment point is attached to aproximal end of at least one anchor prior to (b).
 22. The method ofclaim 21, wherein a distal end of the anchor is attached to the heart.23. The method of claim 22, wherein the anchor is attached to the heartvia an anchoring element.
 24. The method of claim 21, wherein the anchoris sutured to the heart.
 25. The method of claim 23, wherein theanchoring element is a hook.
 26. The method of claim 23, wherein theanchoring element is a clip.
 27. The method of claim 23, wherein theanchoring element is configured to attach to the wall of the leftventricle.
 28. The method of claim 23, wherein the anchoring element isconfigured to attach to a papillary muscle of the heart.
 29. The methodof claim 20, wherein a distal end of at least one anchor is attached tothe heart prior to (b).
 30. The method of claim 29, wherein a proximalend of the anchor is attached to the anchor attachment point on themitral valve prosthesis.
 31. The method of claim 29, wherein the anchoris sutured to the heart.
 32. The method of claim 29, wherein the anchoris attached to the heart via an anchoring element.
 33. The method ofclaim 32, wherein the anchoring element is a hook.
 34. The method ofclaim 32, wherein the anchoring element is a clip.
 35. The method ofclaim 32, wherein the anchoring element is configured to attach to thewall of the left ventricle.
 36. The method of claim 32, wherein theanchoring element is configured to attach to a papillary muscle of theheart.
 37. The method of claim 20, wherein the anchor comprises abiocompatible material.
 38. The method of claim 20, wherein the anchoris configured to function as an artificial chordae.
 39. The method ofclaim 20, wherein the expandable outflow region further comprises atleast two commissural sealing members.
 40. The method of claim 20,wherein the expandable outflow region further comprises two or morecommissure posts, wherein ends of the engagement arms are each coupledto one of the commissure posts.
 41. The method of claim 20, wherein thedelivery device is inserted transfemorally into the left ventricle ofthe heart.
 42. The method of claim 20, wherein the delivery device isinserted transseptally into the left ventricle of the heart.
 43. Themethod of claim 20, wherein the delivery device is insertedtransapically into the left ventricle of the heart.